Ein neues Chloropalladat(II): BaPdCl4

A New Chloropalladate(II): BaPdCl₄ BaPdCl₄ was prepared through reaction of barium chloride and palladium dichloride (molar ratio 2:1) with the aid of the Bridgman technique. According to a X‐ray single crystal investigation, BaPdCl₄ crystallizes with the orthorhombic crystal system (space group Pbcn (No. 60), Z = 4, a = 686.7(1), b = 1258.8(2) pm, c = 750.2(2), R_all = 0.0383). The crystal structure is built up from square planar [PdCl₄] units which are linked together by Ba²⁺ ions in an eightfold coordination.     

[Ag(NH3)2]ClO4: Kristallstrukturen,Phasenumwandlung, Schwingungsspektren

[Ag(NH₃)₂]ClO₄: Crystal Structures, Phase Transition, and Vibrational Spectra [Ag(NH₃)₂](ClO₄) is obtained from a solution of AgClO₄ in conc. ammonia as colourless single crystals (orthorhombic, Pnmn, Z = 4, a = 795.2(1) pm, b = 617.7(1) pm, c = 1298.2(2) pm, R_all = 0.0494). The structure consists of linearly coordinated cations, [Ag(NH₃)₂]⁺, stacked in a staggered conformation and of tetrahedral (ClO₄)^‐ anions. A first order phase transition was observed between 210 and 200 K and the crystal structure of the low‐temperature modification (monoclinic, P2/m, Z = 4, a = 789.9(5) pm, b = 604.1(5) pm, c = 1290.4(5) pm, β = 97.436(5)°, at 170 K, R_all = 0.0636) has also been solved. Spectroscopic investigations (IR/Raman) have been carried out and the assignment of the spectra is discussed.     

Kristallstrukturen von Na3TiCl6 und K3TiCl6

Ternary Halides of the Type A₃MX₆. IX Crystal Structures of Na₃TiCl₆ and K₃TiCl₆ Light yellow single crystals of Na₃TiCl₆ and K₃TiCl₆ are obtained from the binary components, TiCl₃ and NaCl and KCl, respectively, in 1 : 3 molar ratios. Na₃TiCl₆ crystallizes with the cryolite type of structure (monoclinic, P2₁/n, Z = 2, a = 668,02(8), b = 709,13(6), c = 981,38(12) pm, β = 90,31(2)°) while K₃TiCl₆ belongs to the K₃MoCl₆ type of structure (monoclinic, P2₁/c, Z = 4, a = 1261,6(2), b = 751,36(8), c = 1210,7(2) pm, β = 108,30(2)°).     

Solid-Phase Synthesis of Thio-oligosaccharides

No protecting groups are present in the highly reactive polymer-bound sugar 1-thiolates 1 , which undergo reactions with sugar triflates 2 to give thio-oligosaccharides 3 in high yield. Tr=trityl=triphenylmethyl, Tf=trifluoromethylsulfonyl, Bz=benzoyl.     

Chlorobis(nitrato‐O,O')(tetraethylene glycol dimethyl ether)neodymium(III), [NdCl(NO3)2(tetraglyme)]: A Novel Heteroleptic Complex

In the crystal structure of [NdCl(NO₃)₂(tetraglyme)] (triclinic, P1, Z = 2, a = 7.814(1); b = 7.9832(9); c = 15.322(2) Å; α = 87.38(1); β = 84.88(1); γ = 79.83(1)°), neodymium is ten coordinate with two transoid chelating nitrate ligands, a chlorine and the five oxygen atoms of the tetraglyme ligand in an irregular array.     

Synthese und Kristallstrukturen der Tetrachlorozinkate SrZnCl4 und BaZnCl4

Synthesis and Crystal Structures of the Tetrachlorozincates SrZnCl₄ and BaZnCl₄ The tetrachlorozincates SrZnCl₄ and BaZnCl₄ are obtained from the respective binary chlorides at 550 °C in silica ampoules. SrZnCl₄ (tetragonal, I4₁/a, Z = 4, a = 650.40(7), c = 1437.0(2) pm) crystallizes with the scheelite type of structure, BaZnCl₄ (orthorhombic, Pnna, Z = 4, a = 724.15(6), b = 986.2(2), c = 947.71(8) pm) belongs to the GaCl₂ type of structure. The coordination polyhedra of the cations are the same in both compounds: Sr²⁺ and Ba²⁺ are surrounded by eight Cl^– (trigon‐dodecahedron), Zn²⁺ is tetrahedrally coordinated. For both compounds no phase transitions could be detected between 140 and 620 K.     

Zwei Galliumfluorid-Ammoniakate: Ga(NH3)F3 und Ga(NH3)2F3

Two Gallium Fluoride Ammine Complexes: Ga(NH₃)F₃ and Ga(NH₃)₂F₃ Two gallium trifluoride ammines, Ga(NH₃)F₃ and Ga(NH₃)₂F₃, are obtained as single crystals through oxidation of gallium metal with NH₄HF₂ (Ga : NH₄HF₂ = 1 : 1.5) and NH₄F (Ga : NH₄F = 1 : 3.5), respectively, at 450 °C and 400 °C. Ga(NH₃)F₃ crystallizes with the non-centrosymmetric space group Abm2 (a = b = 544.6(2) pm, c = 986.6(4) pm) forming two-dimensional layers of [Ga(NH₃)F₅] octahedra. The addition of another NH₃ molecule in Ga(NH₃)₂F₃ (orthorhombic, Immm, a = 700.0(3) pm, b = 724.7(2) pm, c = 393.1(1) pm) leads to one-dimensional rods of [Ga(NH₃)₂F₄] octahedra running parallel [001] which are stacked in the [010] direction. Infrared spectra suggest hydrogen bonding (N–H…F) in Ga(NH₃)F₃, for Ga(NH₃)₂F₃ an unequivocal statement is not possible.     

Molecular and Crystal Structures of CpSmX2(THF)3 (X = Br,I)

The reaction of Cp₂Sm(THF) with 1,2-dibromoethane or 1,2-diiodoethane leads to an equimolar mixture of Cp₃Sm(THF) and CpSmX₂(THF)₃ (X = Br, I). CpSmBr₂(THF)₃ crystallizes in the monoclinic system (P2₁, Z = 2, a = 804.6(1), b = 1507.6(2), c = 913.8(1) pm, β = 107.36(1)°, R₁ = 0.0327, wR₂ = 0.0578), while CpSmI₂(THF)₃ is orthorhombic (Pna2₁, Z = 4, a = 1950.6(3), b = 1377.1(2), c = 831.93(9) pm, R₁ = 0.0438, wR₂ = 0.0412). The ligand arrangement around the formally eight coordinate Sm atom is a distorted octahedron with the centroid of the Cp-ring and one THF-molecule in the apical positions, whilst the halides are transoid in the equatorial plane.     

Synthese und Kristallstrukturen der Samarium-Komplexe [SmI2(DME)3] und [Sm2I(NPPh3)5(DME)]

Synthesis and Crystal Structures of the Samarium Complexes [SmI₂(DME)₃] and [Sm₂I(NPPh₃)₅(DME)] When treated with ultrasound, the reaction of samarium metal with N-iodine-triphenylphosphaneimine in 1,2-dimethoxyethane (DME) leads to the two samarium complexes [SmI₂(DME)₃] ( 1 ) and [Sm₂I(NPPh₃)₅(DME)] ( 2 ), which are separated from each other by fractional crystallization. 1 could be isolated in two different crystallographic forms, namely as brownish black crystals ( 1 a ) and as violet-black crystals ( 1 b ), both of them are characterized by crystal structure analyses. 1 a : Space group P2₁/c, Z = 4, lattice dimensions at –80 °C: a = 1459.4(1), b = 1314.4(1), c = 2293.6(2) pm, β = 99.245(8)°, R = 0.0344. The structure of 1 a holds two crystallographically independent molecules [SmI₂(DME)₃], in which the samarium atoms have coordination number eight. The two individuals differ from each other particularly in their I–Sm–I bond angles, which are 157.94 and 178.45°. 1 b : Space group P2₁, Z = 2, lattice dimensions at –80 °C: a = 849.4(3), b = 1060.1(3), c = 1235.1(6) pm, b = 93.86(5)°, R = 0.0251. 1 b has a molecular structure similar to that of 1a with a bond angle I–Sm–I of 158.40°. The phosphoraneiminato complex [Sm₂I(NPPh₃)₅(DME)] ( 2 ) forms colourless, moisture sensitive crystals which contain two molecules DME per formula unit. 2 · 2 DME: Space group P1, Z = 2, lattice dimensions at –80 °C: a = 1405.0(4), b = 1656.5(3), c = 2208.3(7) pm, α = 89.60(3)°, β = 72.96(4)°, γ = 78.70(3)°, R = 0.0408. In 2 the two samarium atoms are linked via the μ-N atoms of two phosphoraneiminato ligands to form a planar Sm₂N₂ four-membered ring. One of the Sm atoms is terminally coordinated by the N atoms of two (NPPh₃)^– groups, thus achieving a distorted tetrahedral surrounding. The second Sm atom is coordinated by the N atom of one (NPPh₃)^– group, by the terminally bonded iodine atom, and by the O atoms of the DME chelate, thus achieving a distorted octahedral surrounding.     

Die Einwirkung von Ammoniumfluorid auf Scandium: Synthese und Kristallstrukturen von (NH4)3[ScF6] und [Cu(NH3)4]3[ScF6]2

Action of Ammonium Fluoride on Scandium: Synthesis and Crystal Structures of (NH₄)₃[ScF₆] and [Cu(NH₃)₄]₃[ScF₆]₂ The action of (NH₄)F on scandium in copper ampoules yields either (NH₄)₃[ScF₆] or ScF₃ and a small quantity of [Cu(NH₃)₄]₃[ScF₆]₂, respectively, depending upon the molar ratio of the educts (NH₄)F : Sc (6 : 1 and 4 : 1, respectively) and temperature. (NH₄)₃[ScF₆] crystallizes with the cryolite type of structure: monoclinic, P2₁/n, Z = 2; a = 650.0(2); b = 651.4(2); c = 949.0(2) pm; β = 90.40(2)°, [Cu(NH₃)₄]₃[ScF₆]₂ is triclinic, P‐1, Z = 1; a = 821.1(2); b = 821.2(2); c = 822.7(2) pm; α = 90.04(3); β = 90.00(3); γ = 90.16(3)°. In its chemical behaviour against (NH₄)F, scandium parallels aluminium rather than gallium.